The beautifully pigmented “Lemon Frost” leopard geckos have pale yellow skin with tiny black dots all over their bodies. With such unique coloring, one reptile breeder was excited to purchase them because he believed they would be a popular household pet. Unexpectedly, these geckos were found to have a genetic mutation connected to skin cancer in humans.
Leopard geckos are the most common type of reptile kept as household pets and are sometimes bred to have rare color patterns on their skin known as morphs. Steve Sykes, a reptile breeder, purchased two rare morph leopard geckos in 2015 for $10,000. They were Lemon Frost geckos, and consequently, Sykes named them Mr. and Mrs. Frosty.

Mysterious White Lumps

Due to the geckos’ rare coloring, Sykes immediately began to breed them and created over 900 Lemon Frosts. While watching them grow, Sykes noticed many babies had small, white lumps growing on their bodies. When Longhua Guo, a geneticist from the University of California Los Angeles, contacted Sykes about learning more about the coloring of geckos, he instead urged that he look into the white lumps on the Lemon Frosts.

SPRINT 1 Mutation Found to be the Cause

The recent PLOS Genetics study “Genetics of White Color and Iridophoroma in “Lemon Frost” Leopard Geckos” found that these white lumps are tumors that result from a genetic mutation on one copy of the gene SPINT1. The SPINT1 gene mutation causes the geckos to overproduce iridophores, which are linked to their pale-yellow pigment and are responsible for the white, skin-cell tumors. Reduced amounts of the SPINT1 gene expression have been previously linked to melanoma in humans, and researchers believe the SPINT1 gene mutation in these geckos causes them to develop tumors. This gene mutation creates many opportunities for these geckos to be used in skin cancer research.

The white tumors developed on 80% of the baby Lemon Frost geckos. Further research is being done to determine why 20% of the geckos did not develop tumors, including the father of the offspring, Mr. Frosty. While there are still some questions, discovering the connection between the Lemon Frost geckos and melanoma is a significant breakthrough in skin cancer research. As researchers continue to monitor the tumors of these geckos, they hope to learn more about how skin cancer progresses and determine why the SPINT1 gene is related to the formation of melanoma and other skin cancers. By learning about the progression of these tumors, researchers are hopeful for the development of new treatments for the disease.

Geckos May Help with Understanding Melanoma

After learning about the Lemon Frost’s gene mutation, Sykes donated all of his Lemon Frost geckos to scientific research and discontinued breeding these geckos. He believes that continuing to breed Lemon Frosts wouldn’t align with his goal of breeding healthy geckos. Since the SPINT1 gene mutation that creates their pale-yellow skin is also responsible for developing tumors, it would be impossible to breed Lemon Frost geckos without the high risk of developing tumors.
While Lemon Frost leopard geckos may not be available as household pets, researchers are optimistic that studying their tumors will further the understanding of the development of skin-cell tumors. Researchers are hopeful that the geckos will be able to be used as models to understand melanoma better. At Pulse ISM, we are excited to learn about this new development because skin cancer is the most common cancer throughout the United States. We are hopeful for the advancement of treatment options.

References
Gamillo, E. (2021). This gecko named mr. frosty and his 900 babies may inspire human skin cancer treatments. Accessed July 8, 2021, via: https://www.smithsonianmag.com/smart-news/reptiles-frosty-yellow-skin-may-reveal-future-treatments-skin-cancers-humans-180978075/

Guo L, Bloom J, Sykes S, Huang E, Kashif Z, et al. (2021) Genetics of white color and iridophoroma in “Lemon Frost” leopard geckos. PLOS Genetics 17(6): e1009580. https://doi.org/10.1371/journal.pgen.1009580

Wilcox, C. (2021). “Lemon frost” leopard geckos’ cancers similar to human melanomas.
Accessed July 8, 2021, via: https://www.the-scientist.com/news-opinion/lemon-frost-leopard-geckos-cancers-similar-to-human-melanomas-68924